fix: ignore "package.json" as config file when it's invalid JSON (#1281)

lib/loadConfig.js

@@ -9,12 +9,14 @@ import { resolveConfig } from './resolveConfig.js'
 
 const debugLog = debug('lint-staged:loadConfig')
 
+const PACKAGE_JSON = 'package.json'
+
 /**
  * The list of files `lint-staged` will read configuration
  * from, in the declared order.
  */
 export const searchPlaces = [
-  'package.json',
+  PACKAGE_JSON,
   '.lintstagedrc',
   '.lintstagedrc.json',
   '.lintstagedrc.yaml',
@@ -27,7 +29,18 @@ export const searchPlaces = [
   'lint-staged.config.cjs',
 ]
 
-const jsonParse = (path, content) => JSON.parse(content)
+const jsonParse = (path, content) => {
+  try {
+    return JSON.parse(content)
+  } catch (error) {
+    if (path.endsWith(PACKAGE_JSON)) {
+      debugLog('Ignoring invalid package file `%s` with content:\n%s', path, content)
+      return undefined
+    }
+
+    throw error
+  }
+}
 
 const yamlParse = (path, content) => YAML.parse(content)
 

test/unit/loadConfig.spec.js

@@ -1,3 +1,4 @@
+import fs from 'node:fs/promises'
 import path from 'node:path'
 
 import makeConsoleMock from 'consolemock'
@@ -177,4 +178,32 @@ describe('loadConfig', () => {
 
     expect(result).toMatchInlineSnapshot(`{}`)
   })
+
+  it('should return empty object ".lintstagedrc.json" file is invalid', async () => {
+    expect.assertions(1)
+
+    const configFile = path.join(__dirname, '__mocks__', '.lintstagedrc.json')
+
+    await fs.writeFile(configFile, '{')
+
+    const result = await loadConfig({ configPath: configFile }, logger)
+
+    expect(result).toMatchInlineSnapshot(`{}`)
+
+    await fs.rm(configFile)
+  })
+
+  it('should return null config when package.json file is invalid', async () => {
+    expect.assertions(1)
+
+    const configFile = path.join(__dirname, '__mocks__', 'package.json')
+
+    await fs.writeFile(configFile, '{')
+
+    const { config } = await loadConfig({ configPath: configFile }, logger)
+
+    expect(config).toBeNull()
+
+    await fs.rm(configFile)
+  })
 })